Building materials

Damp-proof membrane

A damp-proof membrane is a plastic sheet used as an underlay for a concrete floor. This waterproof sheet is laid between the insulation layer and the sand base, and offers the concrete protection against damp. The concrete is then poured on top of the insulation. Common examples include:

Polypropylene membrane - a sheet membrane fixed with clips and tape.

Epoxy damp-proof membrane - an epoxy resin for suppressing residual rising damp in concrete. Applied by brush or roller in one or two coats.

Ground sheeting

Available from most builders' merchants, ground sheeting is made from a permeable material that allows water through but not soil particles or silt.

Guy ropes

Guy ropes are used for supporting reinforcing rods in their correct upright position whilst the concrete sets.

Flexible board

A flexible, fibrous board available in pre-cut strips used for creating expansion joints in large concrete pads.

Foil-backed building paper

Paper with a foil backing used to create a vapour barrier for insulation purposes.

Masonry bolt

Also known as an expansion bolt, the masonry bolt consists of a screw fixing threaded through a metal sleeve. A hole is drilled into the masonry the same depth and diameter (or a fraction larger) as the masonry bolt. The screw fixing is inserted into the hole and as the bolt is tightened, the sleeve expands against the sides of the hole producing a very secure fixing.

Membrane clips

Plastic clips for securing a damp proof membrane to the wall. The clips are hammered into pilot holes that have been drilled through the membrane and into the wall.

Polythene sheeting

Heavy-duty polythene sheeting is used as dust sheets, temporary roofing and as a vapour barrier for insulation purposes.

Reinforcing rods

These are bars embedded in the concrete footing used when constructing a screen wall. The pilaster blocks are lowered over these rods and secured with mortar. The rods make the pier more robust and sturdy so they cope with the strains associated with a wall.

Wall profiles

Wall profiles are metal fixings positioned at the point where an existing wall and a concrete block partition wall join. The connectors are designed to strengthen each end of the partition wall. Also known as metal connectors, they should be fitted perfectly straight to ensure a level partition wall.

Wall ties

Wall ties made from galvanized metal are used in the construction of cavity walls to connect the inner and out leaves or walls. They can also be used to join a new wall to an existing wall. There are various types of wall tie available but the three most common are the butterfly tie, fishtail tie and the mesh strip.

Weed proof membrane

Weed proof membrane is made from a permeable material that allows water through but not weeds. It is very similar to ground sheeting.

Doorset

A doorset is a complete unit where the door and frame are pre-fitted and can be fixed directly into the rough opening.

Building paper

Building paper classified as BS1521 Class A is a waterproof paper used for insulation. Building paper is also available for insulation with a foil backing.